test 3 giardia and trichomonas Flashcards
What is an axostyle?
tube like organelle in some flagellates. extends from the area of the kinetosome to the posterior end.
What is a kinetosome?
basal bodies specifically found in ciliates.
Where does Trichomonas vaginalis? T. hominis? T. tenax? T. foetus?
T. vaginalis lives in the reproductive tract.
T. hominis lives in the gut.
T. tenax lives in the mouth.
T. foetus parasitizes cattle.
How long can Trichomonis live outside the body?
only 1-2 hours, or up to 24 if in urine.
What about a T. vaginalis infection causes vaginitis?
Desquamation and inflammation
Describe the life cycle of T. vaginalis.
Gets passed from person to person by sexual intercourse. In the reproductive tract the parasite multiplies by binary fission.
Where are the most common sites of a T. vaginalis infection?
Urethra in men.
Vagina in women.
What are the symptoms of T. vaginalis infection?
Women: Creamy, frothy discharge; itching, burning; dysuria.
Men: asymptomatic. ocasionally urethritis
How does T. vaginalis cause cell death?
secreted proteases at the site of parasite attachment.
What is the treatment for T. vaginalis?
oral metronidazole
What is the undulating membrane?
little wavy thing on the parasites body.
How many flagella does T. vaginalis have?
4
Why is a T. fetus such a big problem?
causes sponaneous abortions within the first trimester.
If a bull is infected with T. fetus what is the solution?
THey are usually culled because no approved therapy is available.
Where does T. tenax live in the mouth?
in the tartar around teeth or in teeth defects. associated with pus pockets.
Which of the 3 human trichomonas is the least common?
T. hominis. lives in the colon.
Who was probably the first person to discover giardia?
Leeuwenhoek
What is the most common flagellate of the human digestive tract? How many cases are there per year?
Giardia intestinalis (lamblia or duodenalis) 200 million
Why is the zoonotic transmission of giardia controversial?
They havent been able to find a clear link between human and animal infections. Giardia could infect a wide range of hosts or each species could have its own type of giardia. Transmission between dogs and humans is rare.
What is the best way to remove the parasite from water? How long can cysts survive in cold water?
Filtration. Chemicals like chlorine wont kill the parasite.
weeks to months.
How much of the population in developing countries is infected with giardia? U.S.?
10%
4%
How does giardia feed? What is the effect?
attaches to the microvilli. causes malabsorption (lactase def. carbs, fats, B12 lost), flattening of the villi, duodenal ulcerations.
How many cases are asymptomatic?
2/3 in endemic areas, 1/3 in an outbreak.
how long is the incubation period?
1-3 weeks.
how long does it take for the symptoms to resolve?
1-4 weeks
How does one diagnose a G. lamblia infection?
cysts or trophozoites in the stool. antigen detection. UGI biopsies or aspirates
What drug is used to treat giardia infection?
metronidazole.
What is the best way to remove pathogens from a water supply?
filter.
